This invention relates to system for coherent radio frequency reception, and more particularly to method and means for increasing the sensitivity of a receiving facility.
In the process of communication with spacecraft, it is sometimes necessary to achieve reception of very low power signals. The signal-to-noise ratio is often so low that signal detection is difficult. To make reception easier, it would be necessary to increase the sensitivity of the receiver, i.e., lower the detection threshold. That would be a difficult task when the receiver design is already at the maximum sensitivity possible with state-of-the-art devices, such as low-noise maser amplifiers mounted immediately behind the horn of a Cassegrain reflector antenna.